In this episode, Samantha's powers are taken away because she shows them to a mortal. However, in several episodes this season and prior, Samantha's relatives and/or other witches/warlocks have used their powers in front of mortals with no worry or fear of them being seen. Having the Witch's Council take her powers away for only this episode does not prove that this is against the rules or forbidden unless they have punished or removed powers from all other incidences.
The series takes place in New England, specifically Connecticut and New York. The rest home would not have an orange tree growing in the front yard, let alone one full with ripe fruit. Unless, this was meant to be a hallucination for only Mrs. Quigley to see.